DE 196 08 872 C1 discloses a breech block for firearms, particularly for repeating firearms, with a cartridge chamber, an external case and a bolt accommodated therein, wherein the bolt features a breech head in the region facing the cartridge chamber and a control piece is arranged within the bolt such that the breech head is unlocked during a backward motion and locked during a forward motion of the bolt lever. However, the breech head is not rotatably mounted in this known breech block. The lock is realized by means of locking elements in the form of balls that are pressed outward against the inner wall of the breech case by a beveled front end face of the control piece during its forward displacement. Although the bolt lever of this firearm has an advantageous rear position, the lock realized by means of the aforementioned balls proved disadvantageous in practical applications.
EP 0 784 194 A2 describes a straight-pull breech block for a firearm, in which the breech head is rotatably mounted about its own axis in a bolt and fixed with respect to its axial motion relative to the bolt by means of a shoulder. A control sleeve features on its front side a control pin, the surface of which is in contact with a control groove. In this firearm, the bolt handle is located on the front end of the breech block for construction-related reasons. This front position of the bolt handle complicates the handling and the fast function of the weapon.
DE 43 05 700 C1 likewise discloses a breech block for a firearm, in which the straight-pull lever is located directly above the trigger and can be conveniently handled due to this position. In this case, however, the lock is realized by means of an expandable sleeve that is not always reliable.
In all three above-described solutions, the control pieces of the respective breech blocks only have a comparatively short stroke that is defined by the position of the lever axis and the contact point with the control piece. The stroke only amounts to approximately 8-10 mm such that the lock can only be realized with an expandable sleeve, balls or a limited rotation by an angle, for example, of up to approximately 20°.
What is needed, therefore, is a breech block, particularly a straight-pull breech block for a firearm, which has a simple design, can be disassembled without tools, and ensures secure locking by means of a rotatable breech head.